// import tmCommon from "@/common/common";

export default {
  install (Vue) {
    // v-dialogDrag: 弹窗拖拽属性
    Vue.directive('dialogDrag', {
      bind (el, binding, vnode, oldVnode) {
        // 自定义属性，判断是否可拖拽
        if (!binding.value) return
        const dialogHeaderEl = el.querySelector('.el-dialog__header')
        const dragDom = el.querySelector('.el-dialog')
        dialogHeaderEl.style.cssText += ';cursor:move;'
        dragDom.style.cssText += ';top:0px;'

        // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
        const sty = (function () {
          if (document.body.currentStyle) {
            // 在ie下兼容写法
            return (dom, attr) => dom.currentStyle[attr]
          } else {
            return (dom, attr) => getComputedStyle(dom, false)[attr]
          }
        })()

        dialogHeaderEl.onmousedown = e => {
          // 鼠标按下，计算当前元素距离可视区的距离
          const disX = e.clientX - dialogHeaderEl.offsetLeft
          const disY = e.clientY - dialogHeaderEl.offsetTop

          const screenWidth = document.body.clientWidth // body当前宽度
          const screenHeight = document.documentElement.clientHeight // 可见区域高度(应为body高度，可某些环境下无法获取)

          const dragDomWidth = dragDom.offsetWidth // 对话框宽度
          const dragDomheight = dragDom.offsetHeight // 对话框高度

          const minDragDomLeft = dragDom.offsetLeft
          const maxDragDomLeft =
            screenWidth - dragDom.offsetLeft - dragDomWidth

          const minDragDomTop = dragDom.offsetTop
          const maxDragDomTop =
            screenHeight - dragDom.offsetTop - dragDomheight

          // 获取到的值带px 正则匹配替换
          let styL = sty(dragDom, 'left') // 为兼容ie
          if (styL === 'auto') styL = '0px'
          let styT = sty(dragDom, 'top')

          // console.log(styL);
          // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
          if (styL.includes('%')) {
            styL = +document.body.clientWidth * (+styL.replace(/%/g, '') / 100)
            styT =
              +document.body.clientHeight * (+styT.replace(/%/g, '') / 100)
          } else {
            styL = +styL.replace(/px/g, '')
            styT = +styT.replace(/px/g, '')
          }

          document.onmousemove = function (e) {
            // 通过事件委托，计算移动的距离
            let left = e.clientX - disX
            let top = e.clientY - disY
            // 边界处理
            if (-left > minDragDomLeft) {
              left = -minDragDomLeft
            } else if (left > maxDragDomLeft) {
              left = maxDragDomLeft
            }

            if (-top > minDragDomTop) {
              top = -minDragDomTop
            } else if (top > maxDragDomTop) {
              top = maxDragDomTop
            }

            // 移动当前元素
            dragDom.style.cssText += `;left:${left + styL}px;top:${top +
              styT}px;`
          }

          document.onmouseup = function (e) {
            document.onmousemove = null
            document.onmouseup = null
          }
          return false
        }
      }
    })

    Vue.directive('dialogChange', {
      bind (el, binding, vnode, oldVnode) {
        // 自定义属性，判断是否可拉伸
        if (!binding.value) return
        const dragDom = el.querySelector('.el-dialog')
        let dragMouse
        // 在弹出框的右下角添加可拉伸标志 class='mouse'
        for (let i = 0; i < dragDom.childNodes[2].childNodes.length; i++) {
          if (dragDom.childNodes[2].childNodes[i].className === 'mouse') {
            dragMouse = dragDom.childNodes[2].childNodes[i]
          }
        }
        // 鼠标拖拽
        dragMouse.onmousedown = e => {
          // content区域
          const content = dragDom.parentNode.parentNode.parentNode.parentNode
          const disX = e.clientX - dragDom.offsetWidth
          const disY = e.clientY - dragDom.offsetHeight

          document.onmousemove = function (e) {
            e.preventDefault() // 移动时禁用默认事件
            // 通过事件委托，计算移动的距离
            const width = e.clientX - disX
            const height = e.clientY - disY

            if (width > content.offsetWidth && height < content.offsetHeight) {
              dragDom.style.height = `${height}px`
            } else if (
              width < content.offsetWidth &&
              height > content.offsetHeight
            ) {
              dragDom.style.width = `${width}px`
            } else if (
              width < content.offsetWidth &&
              height < content.offsetHeight
            ) {
              dragDom.style.width = `${width}px`
              dragDom.style.height = `${height}px`
            }
          }
          document.onmouseup = function (e) {
            document.onmousemove = null
            document.onmouseup = null
          }
          return false
        }
      }
    })
  }
}
